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ferved that thefe never have any ftrings ifluing from them, as the other lands have. Philof. Tranf. N" 69.
SELLA, among the Romans, a chair in which the old and infirm were carried by fervants through the city, and in journeys. Sometimes "the phyficians prefcribed it as an ex- ercife. Pitifc. in voc.
Sella curulU, among the Romans. SeeCuRULE chair, Cycl.
SELLIGA, in the materia medica, a name by which fome authors have called the nardm Celtics, or Celtic fpikcnard of the fbops. Ger. Emac. Ind. 2.
SELLI, EiWioi, in antiquity, an appellation given to thofe who firft delivered oracles. Thefe, according to Strabo and Euftathius, were men, and the name felli is faid to come from Sella, a town in Epirus, or from the river called by Homer Selleis. Potter, Archaeol. Grac. 1.2. c. 8. Tom. I. p. 267, feq.
SEL rZER-wa/fr, die name of a mineral water of Germany, which arifes near Neider Seltz, and is now ufed in England and many other countries.
We called it Seltz, or Seltzer water, and the phyficians pre- fcribe it in many cafes, as fcurveys, fpafmodic affections, and in confumptions ; in the laft cafe, mixing it with afle's miik.
Hoffman, in his examination of the principles of this water, obferves, 1. That on the mixing any acid with it, whether it be a weak or a ftrong one, there is an immediate effer- vefcence ; and on the mixing it with Rhenifh wine and fu- gar, there is a very remarkable emotion and noife, and the whole body of the liquor appears milky for fome time. 2. If they are mixed in equal quantities with fine old Rhenifh wine alone, they become turbid, and acquire a brown co- lour, with a caft of reddifbnefs; like that produced by mixing oil of tartar, or the urinous fpirit of fal armoniac, with good wine. 3. The tafte of thefe waters is not of that penetrating, fubacid kind, which moft of the other mineral waters are of, but rather has a flavour like that of a diluted folution of a lixivial fait. 4. On putting powder of galls in- to them, they do not become purple, nor do they blacken the ftools of thofe who drink them. 5. On adding oil of tartar to them they become milky, but throw down no pre- cipitate. 6. A quart of thefe waters gently evaporated, yields a drachm and twelve grains of a faline matter, and this diffolved and filtrated, yields, on a fecond evaporation, two fcruples of a pure alkaline fait. This fait diffolved in water, and added to a folution of corrofive fublimate, pre- cipitates a yellow powder, or turbith mineral ; and mixed with an infufion of rhubarb, gives it a reddifh colour ; mixed with fal armoniac, it raifes a pungent fmell. 7. A quart of this water being faturated with fpirit of vitriol, to the ceaf- ing of the ebullition on dropping it in, and afterwards gently evaporated, affords a drachm and a half of fait, no way diftinguifhable from tartarum vitriolatum.
8. No medicinal water is fo fubjed~t. to fpoil and corrupt as this in the keeping ; for which reafon the jars muft be well filled, and nicely fecured with found corks, pitched over.
9. If a quantity of this water be fet for a day or two in an open veflcl, it wholly lofes its natural flavour, and taftes only as if oil of tartar had been mixed with common water : in this change it is obfervable alfo, that there is no earthy matter precipitated.
It appears from all thefe obfervations, that this water a- bounds with an alkaline fait in a much greater quantity, than any other of the known mineral waters ; and it feems to contain no particle of the common ingredients of the other mineral waters, which are a ferrugineous earth, and a bitter purging fait, of the nature of Glauber's fait. Hence it does not purge by the belly, but generally goes off by urine. It is one of the mildeft, and molt innocent of all the mi- neral waters, and may be taken by perfons of the weakeft conftitution. Hoffman, Opera, Vol. c. p. 144.
SEMAMPLEXICAULE leaf. See Leaf:
SEMBELLA, among the Romans, a fmall filver coin, equal in value and weight to half the libella. Pitifc. in voc. See the article Libella.
SEMICIRCULARIS palpebrarum mufculus, in anatomy, a name given by Spigelius, and fome others, to one of the mufcles of the face, called by Albinus and Winflow the mufculus orbicularis palpebrarum. See MuscULUS.
SEMI-CUBICAL parabola, a curve of the fecond order wherein the cubes of the ordinates are as the fquares of the abfcifTes. Its equation is axx=y 3 .
SEMI-DITONUS, in mufic, is ufed by fome writers as Sa- linas, for the third minor.
SEMIFLOSCULOUS, in botany, a term ufed to exprefs the flowers of a certain clafs of plants, of which the dande- lion, hawkweed, and the like, are kinds. This fort of flower confifts of a number offemtflofculi, which are either difpofed into one or more circles, and all compre- hended in the fame cup, which often becomes inverted as the flower ripens. Thefe femifiofcules are petals, hollow in their lower part, but in their upper half are flat, and con- tinued in the fhape of a tongue. Thefe are often feparated from each other by intermediate leaves, and are placed up- on the embryo fruit, from which there ftands out a flender
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capillament, divided at the end into two parts; often carried beyond the vagina, fupportcd by five props. The embryos are placed in the thalamus, or bottom of the cup, and fi- nally become feeds, fometimes winged with down, fome- times naked, fometimes coronated, and fometimes foliated. See Tab. i. of Botany, Clafs i. Tourn. Lift. p. 4.67
SEMI-INTEROSSEUS indict), a fmall fhort flat flc-% muf- cle, very like the antithenar, or internal Jmi-'mteraJJius of the thumb. It is fituated obliquely on one fide of that of the thumb, between the firft phalanx thereof, and the firft metacarpal bone. It is fixed by one end to the outfide of the bafis of the firft phalanx of the thumb, and a little to that bone of the carpus, by which this phalanx is fupported ; and by the other end it is fixed near the head of the firft phalanx of the index, on that fide next the thumb. It lies almoft parallel to the antithenar, crofting it a little; this mufcle lying on the convex fide of the hand, and the an- tithenar on the concave. Win/low's Anatomy, p. 202.
SEMILUNARES cochlea, in natural hiftory, the name of a genus of fea (hails, fo called, from their having femicircular mouths. See Tab. of Foffils, Clafs 9. and Tab. of Shells, N° 6.
The characters of the genus are thefe. They are univalve fhells of a compafl body, with a flat femicircular, and often dentated mouth. Some of the fpecies have exerted apices, and fome depreffed.
There are many diftinitive and fpecific charaflers in the fe- veral fpecies of this genus, which arrange together confi- derable numbers of the fpecies under each. Thus the ne- rita, which are of this genus, are fome of them umbili- cated, and others have teeth, and a kind of gums. The frail kinds, diftincfly fo called, that fall under this »enus, are very different from the nerita, in that they have no teeth, no gums, and no palate. The term femilunares co- chlea was invented by Rumphius to exprefs their mouths, being of the fhape of half of a circle. Bonani is of opinion that the nerita were fo called, from their being born of the fea, and called by a name expreftive of that origin by way of eminence, as an honour to their watery parent. To make out the juftice of this derivation, it was neceffary to fuppofe the turita more beautiful than other fhells ; and in order to give them a claim to this cha- racter, the author has introduced into the family of the ne- rita the trumpet fhells and porcellanes. Some authors have called them natrices, from their fwimming, affirming that they fwim in the manner of the nautilus, by letting their mouths before the wind. This is an opinion as old as Pliny, but it is as erroneous as many others of the opinions of that au- thor. The nerita generally inhabit caverns in the fides of rocks, and ufually ftick fall to the ftone. Bonani, Recrcat. Ment. et Ocul. p. 56. Jldrovand. de Teftac. 1. 3. c. 80. Plin. 1. 9. c. 33.
All the fpecies of the femilwiar (hells have few convolutions, and have the extremity of the voluta fmall, and ufually ftanding a little out.
The fpecies of the femilunar cochlea are thefe, as arranged under the two general divifions of dentated nerita, and um- bilicated cochlea. I. The dentated nerita, commonly called the gum-jhell. 2. The bloody tootli-nerita. 3. The ox-pa- hte-nerita. 4. The ftriated and puncfulated nerita. This fpecies, when robbed of its outer coat, and polifhcd, af- fumes a very different appearance, and is feen in the cabi- nets of the curious, under the name of a fafciated nerita with black and yellow variegations. 5. The canaliculated nerita. 6. The furrowed nerita. 7. The thruBi-nerita. 8.The partridge-?7en'ta.
Of the nerita which have no teeth, the following are the known fpecies. 1. The jafper-wrfra with a long beak. 2. The jafper-lwifa with an operculum. 3. The lemon- coloured pez-nerita. 4. The yellow rxz-nertta. 5. The prickly nerita. 6. The reticulated nerita. 7. The nerita va- riegated with black fpots. 8. The red and white fafciated nerita. 9. The lightly ftriated green nerita. 10. The un- dulated nerita.
Of the umbilicated frails, we have the following fpecies. I. The long umbilicated cochlea. 2. The cochlea with an exerted apex. 3. The cochlea with a depreffed apex. 4. The tefticulated cochlea. 5. The hermit cochlea. 6. The umbo- nated cochlea. 7. The fmall nipple cochlea. 8. The heavy white cochlea. And 9. the orange-coloured cochlea. Hift. Naturel. Eclairc. Part 2. p. 256. SEMIMEMBRANOSUS, in anatomy, a long thin mufcle, partly tendinous, and fituated on the backfide of the thigh, a little toward the infide.
It is fixed above by a ftrong broad tendon, or long aponeu- rofis, in the irregular obtufe, prominent line, which goes from the acetabulum to the tuberofity of the ifchium, a little above the infertion of the feminervofus, and between thofe of the gemellus inferior, and quadratus; mixing fome fibres with the triceps tcrtius. From thence it runs down flefhy, in an oblique direction, behind the inner condyle of the os femoris; below which it terminates in a thick tendon, which is inferred in the pofterior and interior fide of the in- ner condyle of the tibia, by three fhort branches ; the firft,
